This is a reconstruction of a Microraptor based on digital overlays of nine fossilized specimens. Microraptor was a pigeon-sized, four-winged dinosaur that lived about 130 million years ago. (Credit: (AMNH/M. Ellison))

Four-Winged Dinosaur's Feathers Were Black With Iridescent Sheen

ScienceDaily (Mar. 8, 2012) — A team of American and Chinese researchers has revealed the color and detailed feather pattern of Microraptor, a pigeon-sized, four-winged dinosaur that lived about 130 million years ago. The non-avian dinosaur's fossilized plumage, which had hues of black and blue like a crow, is the earliest record of iridescent feather color. The findings, which suggest the importance of display in the early evolution of feathers, will be published in the March 9 edition of the journal Science.

The researchers also made predictions about the purpose of the dinosaur's tail. Once thought to be a broad, teardrop-shaped surface meant to help with flight, Microraptor's tail fan is actually much narrower with two elongate feathers. The researchers think that the tail feather was ornamental and likely evolved for courtship and other social interactions, not for aerodynamics.

"Most aspects of early dinosaur feathering continue to be interpreted as fundamentally aerodynamic, optimized for some aspect of aerial locomotion," said Julia Clarke, one of the paper's co-authors and an associate professor of paleontology at The University of Texas at Austin. "Some of these structures were clearly ancestral characteristics that arose for other functions and stuck around, while others may be linked to display behaviors or signaling of mate quality. Feather features were surely shaped by early locomotor styles. But, as any birder will tell you, feather colors and shapes may also be tied with complex behavioral repertoires and, if anything, may be costly in terms of aerodynamics."

These findings also contradict previous interpretations that Microraptor was a nocturnal animal because dark glossy plumage is not a trait found in modern nighttime birds.

This research was funded by the National Science Foundation, the Air Force Office of Scientific Research, the Natural Science Foundation of China, the Beijing Municipal Bureau of Human Resources, the Beijing Academy of Science and Technology, and the American Museum of Natural History.

Other authors on the paper include Qingjin Meng, and Quanguo Li, of the Beijing Museum of Natural History; Liliana D'Alba of the University of Akron; Mick Ellison and Rui Pei of the American Museum of Natural History; and Jakob Vinther of The University of Texas at Austin and Yale University.